The present invention relates to an apparatus for transmitting multimedia data including audio data in real time on the internet protocol (IP) network typically represented by Ethernet.
Recently, a LAN communicating apparatusxe2x80x94including at least one telephone and allowing voice communication through local area network (LAN) or the internetxe2x80x94has been permeated in the market.
FIG. 11 is a block diagram illustrating a structure of a conventional LAN communicating apparatus. A LAN telephone communicating apparatus 1110 comprises the following elements:
(a) a telephone interface 1104 for hooking up a telephone 1108;
(b) a voice-processor 1102 for providing a voice stream from the telephone-interface 1104 with processes such as echo-cancellation, coding and exchanging;
(c) a voice IP processor 1101 for IP packetizing the voice stream supplied from the voice-processor 1102; and
(d) an upstream LAN interface 1106 for coupling LAN communicating apparatus 1110 to an upstream LAN 1107 (e.g. a private branch exchange (PBX) LAN).
For instance, a user in an office has a LAN terminal 1109 (e.g. a personal computer including a 10 BASE-T terminal) and a telephone 1108. When the user hooks up both these apparatuses to the upstream LAN 1107, the telephone 1108 is hooked up to the LAN communicating apparatus 1110, and the LAN terminal 1109 is either hooked up directly to the LAN 1107 or hooked up to a LAN coupling device 1103 such as a repeater hub or a switching hub.
In the LAN communicating apparatus 1110 structured above, a larger traffic in the upstream LAN 1107 delays voice data substantially, and this interferes with the communication, because the LAN 1107 cannot control which traffic goes first, the data traffic or the voice traffic.
In other words, the conventional structure hooks up the LAN terminal and the LAN communicating apparatus to the upstream LAN on equal terms with each other. Therefore, a priority control over the LAN terminal and the LAN telephone communicating apparatus, i.e. which traffic goes first, fully depends on a router, or a switching hub such as a media-access-control (MAC) frame switcher. In particular, when an entrance of the upstream LAN is coupled to a shared-type network such as a repeater hub, the priority control over those two, i.e. which traffic goes first, is impossible.
When a user wants to hook up both the LAN terminal and the telephone to the upstream LAN, each connection requires respective connectors and wires in conventional manner. This increases the cost and makes the operation, as well as maintenance complicated.
The present invention aims to solves the problems discussed above in coupling both a LAN terminal and a telephone to a LAN.
A LAN communicating apparatus of the present inventionxe2x80x94hooking up a telephone and a LAN terminalxe2x80x94for communicating between the LAN and the telephone or the LAN terminal, comprises the following elements:
(a) a telephone interface for hooking the telephone;
(b) a downstream LAN interface for hooking up the LAN terminal on a down stream side; and
(c) a bridge processor for providing voice data from the telephone interface and data sent through the downstream LAN interface with a bridge process.
This structure allows the voice data to be sent to the upstream LAN advantageously over data-packet supplied from the LAN terminal. Therefore, if the LAN terminal belonging to the downstream LAN sends volume of data, voice data from the telephone can be transmitted without delay.
Further, a traffic controller is added to the structure discussed above so that the controller can monitor flow-in volume and a sender""s address of MAC frames supplied from the upstream LAN. When determining that the flow-in volume substantially affects the voice traffic from the telephone, the controller instructs the sender to regulate the volume of MAC frames to be sent out. As a result, delay of voice data due to data congestion between the LAN communicating apparatuses on the LAN can be avoided.
Another LAN communicating apparatus of the present invention comprises the following elements:
a LAN interface;
a telephone interface; and
a hybrid interface.
The hybrid interface is formed of an N-conductor connector, and the pins used for the LAN terminal out of N-pins are connected to the LAN interface, and the other pins not used for the LAN terminal are connected to the telephone interface. This N-conductor connector thus hooks up both of the LAN terminal and the telephone.
As a result, the wiring cost to the LAN terminals can be reduced and such unified connector allows the operation and maintenance of the system to be substantially easy.
The present invention also provides a distribution connector which can couple both the LAN terminal and the telephone to the LANxe2x80x94operating based on the same principal as discussed above.